Boring-bar.



E. C. SCHMELZKOPF.

BORING BAR.

APPLICATION m) Aue.8, 1914..

Patented June 29, 1915.

W Mn UNITED STATES PATENT QFFICE.

EDWARD C. SGHMELZKOPR'OF MADISON, WISCONSIN, 4SSIGNOR TQ GISHOL T MACHINE COMPANY, OF MADISON, WISCONSIN, A CORPORATION OF WISCONSIN.

BORING-BAR.

Specification of Letters Patent.

Patented June 29, 1915.

Application filed August 8, 1914. Serial No. 855,796.

' nor-F, a citizen of the United States, residing at Madison, in the county of Dane and State of Wisconsin, have invented certain new and useful Improvements in Boring-Bars, of which the following is a specification.

My present invention pertains to improvements in boring bars, the construction and advantages of which will be hereinafter set forth, reference being had to the annexed drawings, wherein:

Figure 1 is an elevation of the bar, with the ends broken away; Fig. 2 an enlarged longitudinal sectional view, showing the cutters and securing shim; Fig. 3 a similar view taken on the line 3-3 of Fig. 2; Fig. 4.- a transverse sectional view, on the line 44 of Fig. 2; Fig. 5 a perspective view of the looking key; and Fig. 6 a perspective view showing the cutters, the key or shim, the adjusting screw, the lock screw, and the key or wrench employed to actuate the adjusting screw and to thereby eflect adjustment of the cutters.

'The main object of the present invention is to provide a cutter bar wherein the cutters may be adjusted to a nicety and locked against movement, the locking mechanism being such that it is not e'asily'displaced, and furthermore, serves to force the cutters inwardly into intimate contact with the adjusting screw employed to determine the set of the cutters.

A further object of the invention is to pro vide an adjusting screw and an actuating driver wrench of such construction that the screw may be readily positioned to effect a relatively small adjustment of the cutters, the wrench carrying a graduated dial adapted to be read in conjunction with a scale or fixed mark upon the body of the bar.

A still further object is to provide a special seating-between the key or shim and the locking key, whereby the parts have a fair and extended contact.

With these and other objects in view, a detail description of the structure follows.

The bar may be said to comprise a front portion 1 and a larger, rear section 2. Extending transversely therethrough, at the junction of 'said sections, is a slot or openin adapted to receivev the cutters 3 and 4, an the locking key 5. The cutters, as will be seen upon reference to Fig. 2, have a straight and extended bearing along their rear edges 6, and are well sustained toward their ends by the largerbody section 2, see dotted lines in Fig. 2. The inner end of each cutter is formed with a half-round no-tch'or recess 7, and a rounded b'earing seat 8, said seat preferably being a little shallower in the direction of the length of the cutter than it is across the end thereof, whereby the inclined face 9 of the adjusting screw 10 bears substantially along a line only of said seat and that in line with the direction of the movement of the cutter. The forward edge 11 of each cutter is inclined or tapered, the inclination being rearwardly toward the outer end or cutting edge of the cutter, and said edges are adapted to coact with similarly inclined or inwardly converging faces 12 formed upon one edge of key 5. Said key or shim is held in place by a pin 13 mounted in a hole or opening 14 formed in thebar, said hole being bored at an angle of, say, 3 to the axis of the bar. The rear face 15 of the pin is milled off at the same angle, whereby said face 15 will have a fair and full bearin against the key, and the forward wall of the opening, while at the same time exerting a wedging effect and forcing the key into conwrench carries a dial 19, graduated as desired, and adapted, when the wrench is positioned, to be read in conjunction with an index or scale 20, Fig. 1, produced upon the body of the bar. By this arrangement, which is at once simple and effective, and not subject to injury by reason of the use of the bar, a fine and predetermined adjustment of the screw and cutters' may be effected. To hold the screw 10 against movement, once the desired adjustment is efl'ected, a locking screw 21, provided with a finger 22, 'is employed, said screw being turned inwardly until the finger, which passes up through the recesses 7 contacts with the lower end of the adjusting screw and binds it securely in place.

spirally-disposed grooves 23 will preferably be formed upon the exterior of the larger section 2, said grooves extending from therein; an

the cutters rearwardly of the barand serv-. ing to remove the chips. the bar is made large, as in the present mstance, and consequently leaves but little space between the bar and the walls of the opening in which the bar is working, these grooves may become essential to afford the necessary clearance and feed for the chips or cuttings.

It isthought that the method of adjusting and locking the cutters will be readily understood from the foregoingdescription, but it may be recapitulated as follows: Assuming that the parts are.in the positions shown in Figs. 2, 3 and 4, and it be desired to reset the cutters, the user will loosen pin 13 and turn screw 10 in or out, as the case may be, say in, and by reading the dial 19 in conjunction with the scale 20 he can determine the exact amount of protrusion of the cutters. Lock screw 21 which, of course, was previously backed out, will then be turned in, locking the adjusting screw and holding it against movement. Pin 13 is then driven home, contact with the cutters 3 and 4, and by reason of the inclined faces 11 and 12, the.

cutters will be drawn inwardly into close contact with the adjusting screw and firmly held. By the employment of the Wedging faces 11 and 12 and by providing fiat and extended bearing faces between the pin 13 and the key or. shim 5, and between the pin and the wall of the opening in which itsis mounted, the parts are securely and'posii tively locked in place.

Having thus described my invention, what.

I claim is:

1. In combination with a boring bar, laterally-extending cutters; means for securing adjustment thereof; a shim or key bearing on the cutters adjacent their inner portions, said shim and cutters having inclined contacting bearing faces; and a pin mounted in the bar and bearing on the shim to force the latter into contact with the cutters.

2. In combination with a erall'y-extending cutters 'adjustably mounted adjusting screw mounted in the bar and hearing at its'inner end against said cutters; a key having inclined eonver 'ng faces bearing upon reversely inclined f a ces formed on the cutters; and a pin mounted in the bar and bearing on the key to force the latter into contact with the cutters.

3. In combination with a boring bar, having a recess formed therein for the recep- Where the body of ing inclined to the to the longitudinal axis forcing the key 5 into locking boring bar, lattion of cutters, and an opening for the reception of a locking pin, said opening belongitudinal axis of the bar; cutters mounted in the recess; a key likewise mounted in the recess and bearing upon the cutters; and a pin mounted in the opening, said pin having a flat bearing face contacting with theadj acent face of the key.

4. In combination with a boring bar, hav

ing a recess formed therein for the reception of cutters and an opening for the reception of a locking pin, said opening being inclined of the'bar; cutters ed in the recess and bearing upon the cutters; and a pin mounted in the opening, said pin having an inclined flat bearing face contacting with the adjacent face of the key, the inclination of'said face being substantially the same as the inclination of the opening.

5. In combination with a boring bar, cutters carried thereby; an adjusting screw carried by the bar for eifecting adjustment of the cutters; a movable from the same; and a graduated dial carried by the driver, said dial being adapted to be read, 'n conjunction'with an index on the bar, upon the rotation of the driver. I

6.. A boring tool, comprising, in combination, abarhaving sections of two diameters;

and cutters' carried thereby at the point of mergence of the two sections, the larger section of. the bar being provided with spirallydisposed grooves rearwardly of the bar.

7. Iircombination with a boring bar, a pair of.:1:'c utters carried thereby; an adjusting screw mounted in-the bar, said screw havingasocketed head; a locking screw for said adjusting screw; means for securing the cutters in adjusted position; a driverfor the adjusting screw, said. driver having a portionzadapted to enter the-socket;-and a graduated dial carried by the driver and adaptedfto be. read in conjunction with an index on' the bar asthe adjusting screw is manipulated.

In testimony whereof I have signed my name to-this specification in the presence of two subscribing witnesses. EDWARD C. SCHMELZKOPF.

Witnesses:

H. J. Penn, 0. M. OLSEN.

driver for the screw and reextending from the cutters 

